Flexible, pure FizzBuzz

fizzbuzz.js

//// Implementation

function play(from, to, rules) {
    const lines = [];
    
    for (let i = from; i <= to; i++) {
        const message = rules
            .filter(([word, predicate]) => predicate(i))
            .map(([word, predicate]) => word)
            .join("");

        lines.push(message || i);
    }
    
    return lines;
}

//// Usage

const lines = play(1, 100, [
    ["Fizz", i => i % 3 === 0],
    ["Buzz", i => i % 5 === 0],
]);

console.log(lines.join("\n"));